MSM Flintlock TOUCH HOLE LINERS Replacement Part Black Powder Muzzleloading | eBay
Vent, Touch Hole Liner, 6-.75mm thread, stainless steel, slotted for easy removal for Investarms produced Lyman Great Plains, Trade, & Deerstalker rifles - Track of the Wolf
Part 6 — High and Low Vent Experiments | BlackPowderMag.com